A system (10) for subatmospheric pressure therapy in connection with healing a surgical or chronic wound includes a wound dressing (20) adapted for positioning relative to a wound bed of a subject and a subatmospheric pressure mechanism (40). The subatmospheric pressure mechanism (40) includes a housing (42) a vacuum source (52) disposed in the housing (42) and associated with a vacuum port (72) a collection canister (60) defining an internal chamber (62) in fluid communication with the vacuum source (52) through the vacuum port (72) and with the wound dressing (20) for collecting exudates removed from the wound bed under influence of the vacuum source (52) a hydrophobic filter (76) in fluid communication with the vacuum source (52) and the internal chamber (62) of the collection canister (60) and a screen (80) disposed proximally of the filter (76). The filter (76) is adapted to prevent exudates from reaching the vacuum source (52) while allowing passage of air to the vacuum source (52). The screen (80) includes compounds (84) for cleaving proteins in the exudates to prevent clogging of the filter (76) by the exudates in the collection canister (60).
